Pressure indicating and relief vale



April 7, 1953 E. H. wm-ENBERG Em 2,633,867

PRESSURE INDICATING AND RELIEF VALVE F'led`00t. 2, 1944.

Arroz/VSV:

Patented Apr. 7, 1953 PRESSURE INDICATIN G AND RELIEF VALVE Edward H. Wittenberg and ArthurrF. Allen, Eau

Claire, `Wis., assignors 'to National Pressure Cooker Company, Eau Claire, Wis., a corpora- Y tion of vVihisconsin Application October 2, 1944, Serial No. 556,718

7 Claims.

Y This invention relates to new and useful improvements in pressure indicating and relief as valve) comprising a weighted body normally supported on a vent pipe secured in a'wall of a pressure chamber, such as the cover of a presi sure cooker, and means Within said body for `sealing the opening in the vent pipe to prevent escape of pressure from the pressure chamber, said `valve being adapted to 'automatically release pressure from the pressure chamber when a predetermined pressure is attained therein, but being provided with means for preventing detachment of the valve body from the vent pipe under normal operating conditions.

A further object is to provide a valve of the `foregoing type having a valve body having an axial bore therein for receiving the upper end of a vent pipe mounted ina wall of a pressure chamber,` and an extensible ring mounted in a groove of the wall of said bore adapted to interf lock with a groove or recess provided in the periphery ofthe vent pipe, thereby to limit axial Y movement of the valve body upon the vent pipe under normal operating conditions, such limited movement permitting pressure within the pressure cooker to unseat a valve member carried by the valve body when `apredetermined pressure is attained within the pressure cooker,

thereby to release excess pressure from the pressure cooker. 1

A further object is to provide a device of the class described comprising a valve body having an axial bore therein open at its lowerend for receiving the upper end of a vent pipe mounted in a wall of a pressure cooker, and a valve member adjustably supported in the upper end of ythe valve body and normally .engaging a seat in the upper end of the vent pipe to prevent the escape of pressure from the pressure chamber under normal operating conditions, and means between the Valve body and the vent pipe for limiting axial movement of the valve body on the vent pipe, such limited movement permitting manual opening oi the valve member, when necessary, and also permitting the valve' body to be blown from the vent pipe should an excessive pressure suddenly ydevelop within the pressure cooker body.

A further object is to provide a valve for pressure` cookers kwhich isesubstantially fool-proof ving the valve member unseated by fluid-pressure Z Y in operation and which Aoperates automatically to release pressure from the pressure cooker when a predetermined pressure is developed therein, whereby a constantpressure may be maintained within the pressure cooker, means also being provided for permitting the valve body to be blown off the vent pipe should the pressure within the pressure cooker reach a predetermined dangerous value, thereby to preventrdamage to the cooker.

Other objects of the invention reside in the simple; and inexpensive construction of the apparatus whereby it may be manufactured in quantity at small cost; in the provision of the snap-ring within the valve body which serves to limit theaxial movement of the valve body on the vent pipe and also to prevent its detachment therefrom under normal operating conditions; in the provision of the valvemember in the upper portionof the valve body whereby the pressure within the cooker may be released therefrom by manually unseating the valve member from the upper end of the vent pipe; and in the .simple means provided for preventing 'relative rotation between the valve body and the vent pipe when the valve member is manipulated to open or close the upper end of the vent pipe.

Other objects, uses and advantages of the invention will appear from the following description, the accompanying drawings and the annexed claims. Y

In the accompanying drawings there has been disclosed a structure designed to carry out the various objects of the invention, but it is to be understood that the invention is not confined to the exact features shown, as various changes may be made within the scope of the claims which follow.

In the drawing:

Figure 1 is asectionalelevation of the pressure indicating and relief valve of our invention showing it in normal operating condition wherein the valve member is sealingly engaged with the upper end of the vent pipe; Y

Figure 2 is aview similar to Figure 1, but showto permit the escape of pressure from the cooker; Figure 3 is a view showing the valve member partially unscrewed to unseat said member from the upper end of the vent pipe to release pressure from the pressure cooker;

Figure 4 is a View showing the snap-ring expanded to permit complete detachment'of the valve-body from the vent pipe, aswhen a predetermined high pressure is attained within the cooker;

Figure is a cross sectional view on the line 5-5 of Figure 1;

Figure 6 is a view showing the vent pipe removed from the cover of the cooker; and

Figure '7 is a view showing the snap-ring detached from the valve body.

The novel pressure release valve herein disclosed is shown comprising a vent pipe 2 having a threaded end portion 3 adapted Vt0 be received .in a threaded socket provided in the cover d of a pressure cooker. The upper portion of the vent pipe is formed with a plurality of longitudinal ribs 5 each provided with a horizontal recess vas clearly illustrated in the drawing. A fluid passage extends lengthwise through the vent pipe and terminates at its upper end in a seat 8.

A valve body, generally designated by the numeral 9, is shown provided with an axial bore Il which is open at its bottom to receive the upper portion of the vent pipe, as Aillustrated in Figures 1 to 4, inclusive. rihe lower portion of the bore li is counter-bored or enlarged, as vshown at l2 in the drawing, to receive a retaining-ring v I3 which is seated against a shoulder it and secured in such position by a suitable pin l5, shown passing through an aperture provided in the Wall of the valve body 9,. f

A relatively smaller counteroore i@ is provided between the counter-bore i2 and the bore Il which, with the upper face of the retaining ring i3, provides an annular groove il adapted to receive a split snap-ring i8.

The inside diameter of the snap-ring iS is slightlyless than the outer diameter of the ribs -5 of the vent pipe, whereby when the valve body -9 is fitted onto rthe vupper end of the vent pipe, the

snap-ring i8 must slightly expand in order to pass over the upper ends of the ribs 5 into the annularly disposed recesses provided in the ribs of lthe vent pipe as shown in Figure `1.

4parts .are assembled as shown in Figures 1, 2 and ,3, the snap-ring limits the relative movement of the valve body upon the vent pipe and prevents the valve body from accidently becoming detached from the vent pipe should the cover 'be inverted.

A valve member, generally designated by the numeral 19, is shown provided with va tapered terminal 2l adapted to engage the seat t provided at the upper end of the vent pipe. The valve member has a threaded portion 22 received in threaded engagement with the upper' portion of the valve body 9 and is provided with a finger knob 23 whereby the valve member may conveniently be manipulated to move its terminal 2! into or out of engagement with the seat E as will be understood. When the valve member is rotated by manipulation of the knob 23, the pin E5 whose inner end is received between adjacent ribs 5 of the vent pipe, prevents relative rotation or" the valve body on the vent pipe as will be best understood by reference to Figure 5, whereby the valve member may readily be moved into or out of engagement with its seat by manual manipulation of the knob 23.

In the normal operation of a pressure cooker provided with a pressure indicating and relief 'valve such as herein disclosed, the parts are in- 4 itially positioned as shown in Figure 1, wherein it will be noted that the entire weight of the valve body is supported upon the valve seat 8 as result of the valve member 2l being in engagement therewith. Should it become desirable to release atmospheric air from the pressure cooker upon initial starting thereof, the valve member may be unseated to the positionshown in Figure 3, whereupon the interior of the pressure cooker is in direct communication with the atmosphere through the passage 1 ,and .the bores provided in the valve body 9. To develop pressure within the pressure cooker the valve tip 2| must be screwed downwardly to the position shown in Figure 1, whereby it will sealingly engage the seat 8 and thus prevent further escape of pressure from the cooker body.

When the pressure within the cooker body reaches a predetermined value, the valve body 9 is moved upwardly by the pressure within the Ycooker as shown in Figure 2, whereby the valve tip 2l is partially unseated to permit excess pressure within the cooker body to escape to the atmosphere as indicated by the arrows. When the valve body is thus elevated by fluid pressure against the valve tip 2i, the snap-ring i8 limits its upward :movement or the opening of the valve member 2l as a result of the snap-ring engaging the upper corners il! of the recesses 6 in the vent pipe, it being understood that thering I8 is carried upwardly ,with the valve body 9. because of normally being .seated upon lthe inner corner 20 of the retaining-ring I3, as clearly shown in VFigure 2. Such partial opening of the valve is suiicient to permit vadequate escape of pressure from the cooker whereby a constant cooking pressure may be maintained therein.

When cooking and processing certain kinds of foods, as, for example, cranberries, split peas. cereals, and the likey which have a tendency to swell more or less during the cooking process and which may also fluff up or bubble more or less, particles of such foods may enter the passage l in the vent pipe and temporarily ciog or obstruct it,

Vso that under normal .operating conditions the pressure within the cooker cannot actuate the valve member I9 when the predetermined maximum cooking pressure is attained within the pressure cooker. Under such conditions the pressure -vvithin the cooker body may eventually rise to a o uire from forty-five to fifty pounds pressure in the cooker body to blow such obstructions out of the vent pipe. Such sudden vrelease of the pressure in the cooker through the vent pipe might cause considerable damage, were the valve body 9 loosely supported upon the vent pipe whereby it could readily be blown therefrom.

In the novel pressure indicating and relief valve herein shown, the valve body cannot be blown from the vent pipe except under extreme conditions when it may become necessary to remove it therefrom to prevent bursting of the pressure cooker body as a result of dangerously high internal pressures. To vpermit the valve body to be blown from the vent pipe under such extreme or unusual conditions, the snap-ring i8 is designed to expand and pass over the upper portions of the ribs 5 of the vent pipe 2, as shown in Figure 4, when the pressurel within the cooker is wellfwi-thin the pressure required to burstthe cooker body. k Y

` Thus, should the congestion in the vent pipe `become so complete as to permit a pressure approximately sixty-five pounds to develop within the cookerbody, then the snap-ring I8 will expand and pass over the upper rib portions of the ventA pipe as hereinbefore stated, -an'd thereby release the valve body from the vent pipe.

" Experience hasshown that in most all cases obstructions accumulatingin the vent pipe are ejected therefrom 'before the pressure within the pressure cooker reaches approximatelysixty-nve pounds, but shouldit exceed that pressure the snap-ring i8 expands and releases the valve body as above stated. By so designing the snap-ring the valve body will rarelybe Vblown from the vent pipe, which is a very desirable feature in that it ,greatly reduces the possibility of damage to prop-v erty or injury to'personswhich maybe about the pressure cooker when it is inoperation.

The body `il of thevalve is provided at its upper portion with an annular shoulder 24 adapted to support an outer sleeve-likeweight 25 indicated in dotted lines in Figure l. A similar sleeve 25 Vmay also be telescoped over the sleeve 25 whereby theV pressure indicating and relief valve may be adjusted for various maximum cooking presn sures, as will be understood. Y

It will be understood that the snap-ring and related portions of the pressure indicating and relief valve may be so constructed as to permit release of the valve body fromrthe ventipipe at pressures other than 65 pounds having regard to thecaution that vthe release pressure selected should lie substantially below the bursting point of the vessel. VThe pressures `mentioned are, therefore, given only by way of example and not by wayrof limitation. l It will be apparent to those skilled in the Vart that theV embodiments herein describedmay be variously changed andmodiiied without departing from the spirit of the invention, and that the invention is capable of uses and has advantages not herein specifically "described, Hence it will be appreciated that the herein'disclosed embodiments are illustrativeV only,A and that our invention is not limited thereto.V

Y We claim as our invention:

1. A pressure indicating and relief valve comprising, in combination, a vent pipe adapted to be secured in a wall of a pressure vessel to provide communication with the interior of the vessel, a body having a bore therein for receiving the upper end of the vent pipe, a valve member in the bore of said body adapted to seat upon the open end of the vent pipe to seal it, and a releasable interlock between the body and the vent pipe, said interlock including cooperating structures associated, respectively, with the body and the vent pipe, said structures being of suchrelative dimensions that they accommodate but limit movement of said body and valve member away from the open end of the vent pipe in response to fluid pressures in the vent pipe within a predetermined range, said structures including resilient means accommodating complete separation of the body and valve member from the vent K pipe in response to uid pressures in the vent pipe in excess of said predetermined rangeVv of pres sures. Y

2. In a pressure indicating and relief valve, in combination, a hollow stem member having a reaches ,approximately `sixty-five pounds, which,

valve seat, a cap member telescoped over J@he stem member and carrying a fluid pressure releasable valve member adapted to (restupon said valve seat, there being a recessin the surface of each of said members `facing the other' member, an interlocking element carried in the recess of one of said members and having a rounded portion projecting into' the recess in the other ofsaid members, one of said recesses being wider than said projecting portion whereby the members have permissible play endwise of each other to allow the valve to unseat under a predetermined iluid pressure, said rounded projecting portion being yieldable whereby fluid pressure endwise'of the cap exerting a predetermined .force in excess of that of said predetermined fluid .pressure is effective to force said projecting portionto ride out of said'one recess to accommodate. separation of the cap from the stem- 3. A pressure indicating andrelief valve comL prising, in combination, a vent .pipeadaptedto be secured in the wall of a pressurevesselto pro.'- vide a communication with'the interior of 'the vessel, a body having a bore thereinfor receiving the upper end of the vent pipe, an adjustable valve member in said bore adapted to seal the open end of the vent pipe by resting thereon, and an interlock between the body and the vent pipe, said interlock including cooperating structures associated, respectively, with the 'body and the vent pipe with said structures being of such relative dimensions that they are adapted to accommodate but normally limit axial movement in `either direction of the body and'its valve member relative to the vent pipe, said structures including resilient means adapted to accommodate movement of the body and its valve member lin one direction relative tothe vent pipe beyond the limit normally defined by said structures, said valve member being adapted to be adjusted rela'- tive to the body whereby the valve is unseated from the vent pipe and the body is supported on the vent pipe by the interlock.

4. The combination ofelaim 3 rwherein a sec- 'ond interlock is provided between the body and the vent pipe, said second interlock including co operating structures associated respectively with the body and the vent pipe with said Astructures 4being of such relativeI dimensions that theylimit 'relative rotation between said bodyand said vent pipe.

5. A pressure indicating and relief valve comprising, in combination, a vent pipe adapted to be secured in a wall of a pressure Vessel to provide communication with the interior of the vessel, a body having a bore therein for receiving the upper end of the vent pipe, a valve member in the bore adapted to seal the open end of the vent pipe by resting thereon, the weight of the body and valve member preventing the escape of the nuid under pressure in the vent pipe until a predetermined operating pressure is achieved, c

response to uid pressures within a predeter- Y mined range, said ring disengaging from one of said grooves in response to fluid pressures in excess of said predetermined range of pressures 1 whereby the body and valve member. may be separated from the vent pipe.

6. A pressure indicating and relief valve comprising, in combination, a vent pipe adapted to be secured in a wall of a pressure vessel to provide communication with the interior of the vessel', a body having a bore therein for receiving the upper end of the vent pipe, a valve member in the bore adapted to seat upon the open end of the vent pipe to seal it, the weight of the body and valve member preventing the escape of the iluid under pressure in the vent pipe until a predetermined operating pressure is achieved, and an interlock between the body and the vent pipe, said interlock comprising an expansible split ring `the mean diameter of which corresponds to the bore in the, body, said ring beingy seated partially in a horizontally disposed groove in the vent pipe and partially in a horizontallyl disposed groove in the body, both of said grooves being wider axiallyl than the thickness of the ring thereby permitting limited axial movement of the body and the valve member relative. to the vent pipe in response to iiuid pressures within a predetermined range, said ring being adapted to be engaged between an upper edge of one groove and the lower edge of the other groove when the uid pressures of said predetermined range exist and being adapted to be cammed out of the groove in the vent pipe when said predetermined range of pressures is exceeded, whereby the interlock is released and the body and valve member may be completely separated from each other.

7. A pressure indicating and relief valve comprising, in combination, a vent pipe adapted to be secured in the cover of a pressure vesselA to provide communication with the interior of said vessel, a body having a bore therein for receiv ing the upper end of the vent pipe, an axialV passageway being provided in the exterior of the Y vent pipe to permit thel discharge of the fluid under pressure from the bore, an adjustable valve member having threaded engagement with the body at. the bottom of the bore and` being adapted to seat upon the open end of the vent pipe, the

posed groove in the inner wall of the body, an interlock comprising a split ring partially seated in each of said grooves, said grooves being wider axially than the thickness of the ring to provide limited axial movement of the body and valve member relative to the vent pipe, the groove in the wall of the body being formed by a recessed portion of the bore of said body anda retainer ring seated in a counterbore in the body, a pin carried by the body xing said retainer ring against movement and extendinginto the axial passageway on the exterior of the vent pipe to limit rotation of the body relative to the vent pipe, said split ring being adapted to limit the extent of movement of the body and valve member relative to the vent pipe when a predetermined range of iiuid operating pressure exists and being adapted to be cammed'from its interlocking` position when fluid pressure in excess of the predetermined range of operating pressures exists, whereby the body and valve member may be completely disassociated from the vent pipe.

EDWARDv H. WITTENBERG. ARTHUR`F. ALLEN.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 37,795 Steinmetz Feb. 24, 1863 821,624 Edison May 29, 1906 833,559 Stebbins Oct. 16, 1906 858,131 Aichele June 25, 1907 875,481 Wilson Dec. 31, 1907 1,428,745 Bayles Sept. 12, 1922 1,519,604 Costello Dec. 16, 1924 1,834,837 Hashimoto Dec. 1, 1931 1,998,444 Clapp Apr. 23, 1935 2,107,704 Kronquest Feb. 8, 1938 2,428,483 Wittenberg Oct. 7, 1947 2,540,583 Ives Feb. 6, 1951 FOREIGN PATENTS Number Country Date 673 Great Britain of 1881 4,081 Great Britain of 1881 78,173 Austria ofl 1919 230,049 Switzerland of 1944 

